Threaded Flanges — Easy to Install, but Proper Installation Requires More Than Meets the Eye

Among the various types of flanges, the threaded flange stands out as a unique option. It requires no welding — simply thread the pipe directly into the flange to complete the connection. Its simplicity, convenience, and elimination of on-site hot work make it a popular choice.

However, while a threaded flange is "easy to install," proper installation is not as simple as it appears. Convenience in one aspect often demands greater attention in another.

Welding-free does not mean attention-free

Many users choose threaded flanges for the low barrier to installation — no certified welders, no welding equipment, just a wrench. For low-pressure small-bore piping, temporary lines, or maintenance and replacement scenarios, this is indeed the fastest solution.

But there is a frequently overlooked issue: a threaded connection is inherently "loose" in nature. Without the fusion of a weld or the preload distribution of bolted flanges, the entire connection's reliability depends almost entirely on the precision of the threads and the quality of installation. Threaded flanges demand high standards for dimensional accuracy, thread quality, and sealing performance. Any deficiency in thread machining or improper installation torque can lead not only to sealing failure but also to damage on the pipe end threads — potentially requiring rework on the entire pipe section.

MIDAS threaded flanges — accurate dimensions, precise threads

MIDAS maintains strict control over several key aspects to minimize uncertainty during assembly.

Thread precision: Manufactured to NPT (American) or BSPT (British) standards, with taper, pitch, and thread angle strictly compliant. Every flange is inspected with thread gauges — go and no-go — to ensure a tight fit with pipe-end threads, eliminating any looseness after installation.

Flange material: Carbon steel and stainless steel options are available in stock, matching the pipe material to prevent galvanic corrosion from dissimilar metal contact.

Sealing face: Available in raised face (RF) or flat face (FF), with surface roughness properly controlled to ensure uniform gasket compression. The sealing face is the foundation of flange reliability — once this is secured, the rest follows.

Pressure rating: Covers Class 150 through Class 600, suitable for most low to medium pressure applications.

When to choose threaded flanges

Threaded flanges offer convenience, but they are not suitable for every application. Consider these three conditions before selecting them:

Operating pressure should not be too high (typically below 2.5MPa). Pipeline vibration should be minimal (otherwise threads may loosen over time). Nominal pipe size should be moderate (typically DN≤100).

As long as these conditions are met, threaded flanges are an excellent choice. Particularly in applications requiring rapid installation, no hot work, or frequent disassembly, their convenience is truly unmatched.

MIDAS threaded flanges — easy to install; proper installation relies on us.

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